Pilot Light Won't Stay Lit When I Release The Knob

Pilot Light Won't Stay Lit When I Release the Knob: Troubleshooting Your Gas Appliance

A flickering pilot light or one that stubbornly refuses to stay lit after releasing the knob is a frustratingly common problem with gas appliances like water heaters, furnaces, and stoves. This issue prevents your appliance from functioning correctly, leaving you in the cold, without hot water, or unable to cook. Instead of calling a costly repairman immediately, let's troubleshoot this problem together. This guide provides a comprehensive, step-by-step approach to diagnosing and solving this persistent issue.

Understanding Your Pilot Light System

Before diving into troubleshooting, let's understand the basics of a pilot light system. The pilot light is a small, constantly burning flame that ignites the main burner when needed. The pilot light receives gas through a small tube and is usually ignited using a knob that simultaneously provides gas and sparks. Releasing the knob usually leaves the gas flow to the pilot light uninterrupted, allowing it to remain lit. However, when the pilot light goes out after releasing the knob, there's a problem somewhere in this system.

Key Components of a Pilot Assembly:

• Gas Valve: This controls the flow of gas to both the pilot light and the main burner.
• Thermocouple: This is a crucial safety device. It's a small metal rod that generates a small electrical current when heated by the pilot flame. This current keeps the gas valve open. If the pilot light goes out, the thermocouple cools, the current stops, and the gas valve closes, preventing gas leaks.
• Pilot Light Assembly: This includes the small burner and the tube that delivers gas to it.
• Igniter (or Spark Electrode): This creates a spark to ignite the pilot light when the knob is pressed. Some older systems may rely on manual ignition instead.

Common Causes of a Pilot Light Going Out After Releasing the Knob

Several factors can cause your pilot light to extinguish after releasing the knob. Let's explore the most common culprits:

1. Weak or Failing Thermocouple:

This is arguably the most frequent cause. The thermocouple might be worn out, dirty, or damaged, failing to generate sufficient electrical current to keep the gas valve open. Over time, the thermocouple can become coated with soot and carbon, hindering its ability to conduct heat effectively. It's also susceptible to damage from high heat or physical impacts.

Solution: Carefully inspect the thermocouple for visible damage, such as cracks or bends. If it appears damaged, replacement is necessary. If it looks intact, you might try cleaning it with fine steel wool or sandpaper, but be gentle not to damage it.

2. Insufficient Gas Supply:

A low gas pressure to the appliance can prevent the pilot light from staying lit. This could be due to a problem with your main gas line, a clogged gas filter, or a malfunctioning gas regulator.

Solution: Check your main gas supply to ensure it’s functioning correctly. If you're comfortable, check your gas filter (usually located close to the gas meter) and clean or replace it if needed. If you suspect an issue with the regulator, contact a qualified gas technician.

3. Clogged Pilot Orifice:

The small hole (orifice) where gas exits to feed the pilot light can become clogged with dust, debris, or spider webs. This restricts gas flow, preventing the pilot from staying lit.

Solution: Use a thin, flexible piece of wire, such as a straightened paperclip, to gently clear out the orifice. Be cautious not to enlarge the hole. A compressed air canister can also be used.

4. Dirty or Blocked Pilot Light Assembly:

Dust, cobwebs, or other debris can accumulate around the pilot light assembly, preventing proper gas combustion. Soot buildup on the pilot burner can also hinder the flame.

Solution: Carefully clean the pilot light assembly with a wire brush or a toothbrush and vacuum the surrounding area. Make sure to turn off the gas supply before doing this.

5. Faulty Gas Valve:

The gas valve itself might be malfunctioning, failing to remain open even when receiving the signal from the thermocouple. This is less common but requires professional attention.

Solution: Unfortunately, you'll likely need a professional gas technician to diagnose and replace a faulty gas valve. Attempting to repair this yourself is dangerous.

6. Incorrect Pilot Adjustment:

The pilot light flame might be improperly adjusted, resulting in it being too small or too weak to adequately heat the thermocouple.

Solution: Refer to your appliance's manual to find the recommended pilot light flame adjustment. Usually, a small, steady blue flame is ideal. There's often a small adjustment screw near the pilot light assembly. Turn it carefully to adjust the flame size.

Troubleshooting Steps: A Practical Guide

Follow these steps systematically to diagnose and fix your pilot light problem:

1. Safety First!

• Turn off the gas supply: Locate the gas shut-off valve for your appliance and turn it off completely. This is crucial for safety before undertaking any repair work.
• Ventilate the area: Ensure good ventilation in the area where you're working, as gas leaks can be hazardous.

2. Visual Inspection:

• Examine the thermocouple: Look for any visible damage or excessive soot buildup. Clean it carefully if necessary, but replace it if damaged.
• Inspect the pilot orifice: Check for any obstructions using a thin wire or compressed air.
• Check the pilot assembly: Clean any dust or debris around the pilot light and burner.

3. Relighting the Pilot Light:

• Turn the gas supply back on.
• Follow the instructions in your appliance's manual: This varies depending on the appliance, but generally involves holding down the knob to ignite the pilot light and keeping it held for a specified time (usually 30-60 seconds) to allow the thermocouple to heat up.

4. Observe the Flame:

• Is the flame strong and blue? A weak, yellow, or flickering flame is a sign of problems.
• Does the flame stay lit when you release the knob? If not, go back and carefully recheck steps 1-3.

5. If the problem persists:

• Check the gas filter: A clogged filter can significantly reduce gas pressure.
• Contact a professional: If you've tried everything and the problem remains, it's time to call a qualified gas technician. Attempting more complex repairs without the proper expertise is dangerous and could lead to further damage or gas leaks.

Prevention and Maintenance

Regular maintenance can significantly reduce the likelihood of encountering this issue.

• Clean the pilot light assembly regularly: This prevents soot buildup and obstructions.
• Check the gas filter periodically: Replace it as recommended by the manufacturer.
• Schedule annual inspections: A professional inspection can identify potential problems before they become major issues.

Conclusion: Keep Your Appliances Burning Bright!

A pilot light that won’t stay lit is a nuisance, but by understanding the underlying causes and following the troubleshooting steps outlined above, you can often resolve the problem yourself. Remember that safety is paramount. If you’re uncomfortable working with gas appliances, or if the problem persists after attempting these solutions, it’s always best to seek professional help from a qualified gas technician. Their expertise ensures the safe and efficient operation of your appliances. By following these steps and undertaking regular maintenance, you can ensure your gas appliances continue to function reliably for years to come.